The present invention relates to a clip comprising a pin and a bush to connect attachment members such as two panels each other.
A clip has been well known which comprises a pin and a bush, wherein a shank of the bush is inserted into holes of attachment members such as two panels to be connected with each other, and then a shank of the pin is inserted into the hollow shank of the bush to enlarge the diameter of the shank of the bush so as to connect the attachment members each other by the enlarged shank of the bush and the flange of the bush. This clip can connect the attachment members to each other only by inserting and pushing the shank of the bush into the holes of the attachment members, which facilitates a fastening operation. In many conventional clips, where the range for panel thickness is widened, a plurality of thick panels can be connected with each other by the enlarged portion of the shank of the bush and the flange of the bush. However, if the panels are relatively thin, the root portion of the shank of the bush cannot be substantially enlarged in its diameter. Consequently, the panels are not sufficiently connected with each other so that the panels tend to be floated from each other. Where the shank of the bush is made longer for the thick panels, the length from the bottom surface of the panels to the end of the bush becomes redundantly long for the thinner panels. Thus, the shank of the bush cannot be maintained in a sufficient stiffness, resulting in lowered resistance to coming-off of the clip. For widening the range for the panel thickness, it has been required to prepare many kinds of clips having various lengths, each matching with a particular panel thickness. In view of this problem, the applicant has developed a clip capable of providing reliable connection and widening the range for the panel thickness.
One type of prior art clip allows a single kind of clip to be applied to a wide range of panel thickness with reliable connection. This clip can connect attachment members each other, for example, two panels, by moving the shank of the pin from a non-diameter enlargement connection position that the shank of the pin is inserted into the shank of the bush and the pin is connected with the bush while keeping the shank of the bush not to be enlarged in its diameter by the shank of the pin, to a diameter enlargement connection position that the shank of the pin is further inserted into the shank of the bush and the end of the shank of the bush is enlarged in its diameter by the end of the shank of the pin. In a fastening operation of this clip, it has been found that an operation for pushing the pin to the diameter enlargement connection position was simple but necessary to push the pin with relatively strong force, which somewhat imposed a burden on operators.
Another type of prior art clip allows for connecting attachment members to each other by moving the shank of the pin from a non-diameter enlargement connection position, that the shank of the pin is inserted into the shank of the bush and the pin is connected with the bush while keeping the shank of the bush not to be enlarged in its diameter by the shank of the pin, to a diameter enlargement connection position, that the shank of the pin is further inserted into the shank of the bush and the end of the shank of the bush is enlarged in its diameter by the end of the shank of the pin. However, since the shank of the bush of this clip is not divisible, it is necessary to make the shank of the pin long. Another type of clip has a cap that is covered over an anchor leg clip. Although this clip has the cap, there is, in this clip, no suggestion for the combination of the pin and the bush to connect panels by pushing the pin into the bush. Further, U.S. Pat. No. 5,850,676 discloses a clip for connecting two panels to each other by moving the shank of the pin from a non-diameter enlargement connection position that the shank of the pin is inserted into the shank of the bush and the pin is connected with the bush while keeping the shank of the bush not to be enlarged in its diameter by the shank of the pin, to a diameter enlargement connection position so that the shank of the pin is further inserted into the shank of the bush and the end of the shank of the bush is enlarged in its diameter by the end of the shank of the pin. Since the shank of the bush of this clip is not divisible, it is necessary to make the shank of the pin long.
According to the present invention, the shank of the bush may be deformed at its root portion to enlarge in its diameter, so that even in thin panels, the panels can be connected with high connecting force to prevent the panels from floating from each other with any undesirable gap between the panels. This provides high resistance to coming-off of the clip and thereby eliminates the needs for making the shank long. Further, the slits provided in each leg allows the load in the operation for pushing the pin to be significantly lowered so as to lighten the load for operators in the fastening operation.
It is therefore an object to provide a clip capable of achieving a sufficient connection force for both thick panels and thin panels even if the clip is required to widen the range for the panel thickness, and capable of allowing its pin to be pushed with a light insertion load in a fastening operation.
In order to achieve this object, according to the present invention, there is provided a clip comprising a pin including a flange and a shank, and a bush including a flange and a shank with the bush having a hollow configuration to receive the shank of the pin, wherein the shank of the bush is inserted into holes of a plurality of attachment members such as panels to be connected with each other, and then the shank of the pin is inserted into the hollow shank of the bush to enlarge the diameter of the shank of the bush so as to connect the attachment members each other by means of the enlarged shank of the bush and the flange of the bush. The clip is characterized in that the shank of the bush includes a plurality of longitudinally extending legs which are divided in the circumferential direction of the shank of the bush; each of the legs includes a thin wall portion, the thin wall portion extending longitudinally from the root portion of the leg adjacent to the flange of the bush to the intermediate portion of the leg with the thin wall portion having a thickness less than that of the other portion extending longitudinally from the intermediate portion to the end of the leg; and each of the legs is formed with a slit extending longitudinally from the root portion to substantially the intermediate portion with the slit having a length greater than the thickness of the attachment members. Thus, even in thin panels, the panels may be connected with desirably maintained high connecting force to prevent any undesirable gap between the panels. This provides high resistance to coming-off of the clip and thereby eliminates the needs for making the shank long. Further, the slits formed in each leg allows the load in the operation for pushing the pin to be significantly lowered, which may lighten the load for operators in the fastening operation.
Preferably, the above clip includes an engagement pawl adapted to engage with an engagement shoulder of the shank of the pin. In that case, the engagement pawl is formed inside each the thin wall portion of the legs of the shank of the bush and at each the root portion of the legs. The shank of the pin may further includes a first small-diameter portion formed at the end of the shank of the pin to receive each the engagement pawl of the legs, and a stopper shoulder formed closer to the end of the shank of the pin than the first small-diameter portion, so that the clip can be at a non-diameter enlargement connection position at which the shank of the pin is inserted into the shank of the bush and the pin flange is away from the flange of the bush with keeping the shank of the bush not to be enlarged in its diameter by the shank of the pin; and a second small-diameter portion formed at the root portion of the shank of the pin adjacent to the pin flange to form the engagement shoulder, and an engagement protrusion formed at each the end of the legs and protruding radially inward, so that the clip can be at a diameter enlargement connection position at which the shank of the pin is further inserted into the shank of the bush and the end of each the legs of the shank of the bush is enlarged in its diameter by the end of the shank of the pin while bringing the pin flange into contact with the flange of the bush, and wherein at the diameter enlargement connection position, the engagement pawl is into engagement with the engagement shoulder of the shank of the pin and the engagement protrusion is into engagement with the first small-diameter portion, so as to make each the end of the legs protrude radially outward. Furthermore, when the pin and the bush are at the diameter enlargement connection position, the pin flange and the flange of the bush may be adapted to have a given clearance therebetween around the entire pin flange.